Petrolatum based compositions (i.e., composition in which the emollient petrolatum comprises greater than or equal to 50% of the composition) are desirable because of the excellent moisturization properties provided by petrolatum. However, it has sensory negatives perceived by consumers. Specifically, because of the oily/greasy and “tacky” (i.e., slightly adhesive or gummy to touch) feel, petrolatum has certain limits to the scope of application.
Silicone oil can improve the sensory aesthetics (oiliness; tackiness) of such petrolatum-based compositions, but use of significant levels of silicone oil (e.g., >10%) can lead to instability of the blend, with the silicone oil tending to separate out as a clear layer over time. That is, even though petrolatum itself is a self-structured oil (structured via long crystals formed by n-alkanes), if too much silicone is blended in (as in the >10% of the subject invention required for sensory improvements), the silicone will normally dilute the petrolatum structure (what we call “softening” the petrolatum) and separate out unless, as applicants have unexpectedly found, the silicone itself is properly structured (e.g., to “match” the properties of the petrolatum).
Unexpectedly, applicants have found that, if the silicone is structured with specific blending ratios of fatty acids (compared to traditional silicone gel thickener/gellants), the silicone in the petrolatum based composition will provide benefits of silicone e.g., less greasy and/or tacky feel of petrolatum) while avoiding the instability caused by silicone and petrolatum interaction, even at the levels of >10% silicone used to provide silicone benefits.
U.S. Pat. Nos. 6,264,963, 6,238,682, 5,849,314, 5,744,146, 5,643,899, 5,558,872, 5,494,657, 5,387,417, 5,308,526 describe generally low-water formulas that contain petrolatum; U.S. Pat. No. 5,643,899 describes compositions which contain cholesterol, acyl ceramides, ceramides, and essential and nonessential fatty acids. Some of these combinations are further enhanced by the addition of known moisturizers such as petrolatum and glycerine. However, there is no silicone oil in this formula.
As far as applicants are aware, there is no reference disclosing petrolatum compositions comprising silicone structured with the specific blending ratios of fatty acid as disclosed by the invention.
In another embodiment, the invention relates to cosmetic compositions comprising the petrolatum based composition.